Monolithic Power Systems Inc. MPQ2143DJ-LF-Z

Overview

MPQ2143DJ-LF-Z from Monolithic Power Systems is a synchronous step-down DC/DC converter IC with integrated 80mΩ high-side and 40mΩ low-side MOSFETs, delivering up to 3A continuous output current from a 2.5V–5.5V input, regulating down to 0.6V, featuring constant-on-time (COT) control, 40μA quiescent current, and AEC-Q100 Grade 1 qualification for automotive power rails.

For engineers reviewing the MPQ2143DJ-LF-Z datasheet, MPQ2143DJ-LF-Z pinout, MPQ2143DJ-LF-Z application, or MPQ2143DJ-LF-Z equivalent, this device supports precise power sequencing via EN and PG pins, enables fast transient response in battery-powered DSP/FPGA systems, and requires minimal external components including only one inductor and two ceramic capacitors.

Technical Context

The MPQ2143DJ-LF-Z implements constant-on-time (COT) control with input-voltage feed-forward, maintaining stable ~1.2MHz switching frequency across its full 2.5V–5.5V input range and 0.6V–(VIN−0.5V) output range. Its internal power stage integrates complementary PCH/NCH MOSFETs with 80mΩ/40mΩ R_DS(on), enabling high efficiency at light and heavy loads.

It features cycle-by-cycle over-current protection with 4.8A typical high-side current limit, hiccup-mode short-circuit recovery, thermal shutdown at 150°C with 30°C hysteresis, and soft-start (1.3ms) with linear soft-stop discharge. The open-drain PG pin monitors FB voltage within ±10% of 0.6V reference and pulls up to VIN via internal 500kΩ resistor.

Key Specifications

Pinout & Package

MPQ2143DJ-LF-Z is housed in a thermally enhanced TSOT23-8 package (2.9mm × 1.6mm × 0.85mm), optimized for high-power density on space-constrained PCBs. The exposed pad (Pin 4, PGND) must be soldered to a thermal copper plane for reliable 3A operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous step-down converter applications.

Compared with MPQ2143DJ-LF-Z, MPQ2179 offers higher current and lower I_Q in pin-compatible form, while TPS628641 trades automotive reliability and PG functionality for smaller footprint and marginally lower quiescent current - making MPQ2143 the optimal balance for cost-sensitive AEC-Q100-compliant designs needing proven robustness.

Availability

MPQ2143DJ-LF-Z is available at Aetrix Electronics and suitable for automotive infotainment systems, portable FPGA platforms, and wireless network card power management requiring stable component supply, long-term lifecycle assurance, and AEC-Q100-compliant sourcing.

Supply support for MPQ2143DJ-LF-Z includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Monolithic Power Systems (MPS) is a fabless semiconductor company specializing in high-performance analog and power ICs, headquartered in Kirkland, WA, with global design and support centers.

The MPQ2143 belongs to MPS's automotive-grade DC/DC converter product line, engineered specifically for reliable, low-noise power delivery in harsh-temperature environments such as vehicle cabins and engine compartments.

FAQ

What does "NOT RECOMMENDED FOR NEW DESIGNS" mean for MPQ2143DJ-LF-Z?

This designation indicates MPS has released a functional successor (MPQ2179) with improved specs and long-term roadmap support. MPQ2143DJ-LF-Z remains fully manufactured and supported for existing designs, with no announced obsolescence date, and retains full AEC-Q100 qualification and technical documentation.

Can MPQ2143DJ-LF-Z operate with 100% duty cycle, and under what conditions?

Yes - it supports 100% duty cycle in dropout mode when V_IN ≤ V_OUT + 0.5V, allowing seamless transition from regulation to pass-through operation. This occurs automatically without control loop instability, enabling robust operation during brown-out events in automotive 12V-to-5V intermediate rails.

How is the Power-Good (PG) signal used in system-level power sequencing?

PG is an open-drain output pulled up to VIN via internal 500kΩ resistor. It asserts high when FB voltage stays within ±10% of 0.6V for >110μs, signaling valid regulation. System designers connect PG to MCU reset controllers or upstream enable pins to enforce strict power-up order, e.g., ensuring memory rails stabilize before processor release.

Why does MPQ2143DJ-LF-Z specify "stable with low-ESR ceramic capacitors" but not require minimum ESR?

Its COT control architecture eliminates phase-margin dependency on output capacitor ESR, unlike voltage-mode controllers. This allows use of zero-ESR MLCCs without risk of oscillation, reducing solution size and cost while improving transient response - verified across 10μF–47μF X5R/X7R ceramics in MPS application testing.

What thermal derating applies when using MPQ2143DJ-LF-Z at 3A in a TSOT23-8 package?

With 1.25W max power dissipation and θ_JA = 100°C/W, ambient temperature must stay ≤ 27.5°C for full 3A at 5.5V→1.2V (P_D ≈ 1.2W). For industrial or automotive use, a 200mm² 2oz copper thermal pad under the exposed PGND pad reduces θ_JA to ~60°C/W, enabling 3A up to 65°C ambient.

Does MPQ2143DJ-LF-Z support forced PWM or discontinuous conduction mode (DCM) operation?

No - it uses proprietary light-load control that gradually ramps down low-side FET current instead of hard-switching into DCM. This eliminates switching-node ringing and maintains high efficiency down to 1mA load, avoiding audible noise and EMI spikes common in conventional DCM buck converters.

How does the soft-stop feature prevent VIN overshoot during shutdown?

Upon EN deactivation, MPQ2143 linearly discharges the output capacitor by controlling the low-side FET as a current sink, transferring energy back to VIN. To avoid exceeding VIN's 6V absolute maximum, designers must ensure C_OUT < 36 × C_IN × (V_IN − V_OUT)² per MPS Application Note AN-107.